Chemical Kinetics

Consider the following first order gas phase reaction at constant temperature A(g) 2B(g) + C(g) If the total pressure of the gases is found to be 200 torr after 23 sec. and 300 torr upon the complete decomposition of A after a very long time, then the rate constant of the given reaction is 10-2 s-1 (nearest integer) [Given : 10(2) = 0.301]

Consider the following reaction A + B C The time taken for A to become 1/4th of its initial concentration is twice the time taken to become 1/2 of the same. Also, when the change of concentration of B is plotted against time, the resulting graph gives a straight line with a negative slope and a positive intercept on the concentration axis. The overall order of the reaction is .

For a reaction A K1 B K2 C. If the rate of formation of B is set to be zero then the concentration of B is given by :

1. (K1 - K2)[A]
2. (K1 + K2)[A]
3. K1K2[A]
4. (K1/K2)[A]

Time required for 99.9\% completion of a first order reaction is times the time required for completion of 90\% reaction.(nearest integer)

Consider the two different first order reactions given below A + B C (Reaction 1) P Q (Reaction 2) The ratio of the half life of Reaction 1 : Reaction 2 is 5 : 2. If t1 and t2 represent the time taken to complete 2/3rd and 4/5th of Reaction 1 and Reaction 2, respectively, then the value of the ratio t1 : t2 is 10-1 (nearest integer). [Given : 10(3) = 0.477 and 10(5) = 0.699]

During kinetic study of reaction 2A + B C + D, the following results were obtained : [figure] Based on above data, overall order of the reaction is .

Consider the following single step reaction in gas phase at constant temperature. 2A(g) + B(g) C(g) The initial rate of the reaction is recorded as r1 when the reaction starts with 1.5 atm pressure of A and 0.7 atm pressure of B. After some time, the rate r2 is recorded when the pressure of C becomes 0.5 atm. The ratio r1 : r2 is 10-1. (Nearest integer)

Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below. [figure] Some details of the above reactions are listed below. [figure] If the overall rate constant of the above transformation (k) is given as k = k1k2k3 and the overall activation energy (Ea) is 400 kJ mol-1, then the value of Ea3 is kJ mol-1 (nearest integer)

Consider the following reaction, the rate expression of which is given below A + B C rate = k[A]1/2[B]1/2 The reaction is initiated by taking 1 M concentration of A and B each. If the rate constant (k) is 4.6 10-2 s-1, then the time taken for A to become 0.1 M is sec. (nearest integer)

The ratio of 14C12C in a piece of wood is 18 part that of atmosphere. If half life of 14C is 5730 years, the age of wood sample is years.